IETF Logo Mail Archive

Re: IPv6 Routing & ND vs. Addressing, (Was: Re: <draft-ietf-6man-rfc4291bis-09.txt>)

David Farmer <farmer@umn.edu> Sat, 15 July 2017 23:37 UTC

Return-Path: <farmer@umn.edu>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 91AAD131566 for <ipv6@ietfa.amsl.com>; Sat, 15 Jul 2017 16:37:48 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.801
X-Spam-Level:
X-Spam-Status: No, score=-3.801 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_SORBS_SPAM=0.5, RP_MATCHES_RCVD=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=umn.edu
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NUkQQSJAX4Ht for <ipv6@ietfa.amsl.com>; Sat, 15 Jul 2017 16:37:46 -0700 (PDT)
Received: from mta-p7.oit.umn.edu (mta-p7.oit.umn.edu [134.84.196.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 992001274D0 for <ipv6@ietf.org>; Sat, 15 Jul 2017 16:37:46 -0700 (PDT)
Received: from localhost (unknown [127.0.0.1]) by mta-p7.oit.umn.edu (Postfix) with ESMTP id 0154CB72 for <ipv6@ietf.org>; Sat, 15 Jul 2017 23:37:46 +0000 (UTC)
X-Virus-Scanned: amavisd-new at umn.edu
Received: from mta-p7.oit.umn.edu ([127.0.0.1]) by localhost (mta-p7.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5otjXLhotGcJ for <ipv6@ietf.org>; Sat, 15 Jul 2017 18:37:45 -0500 (CDT)
Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mta-p7.oit.umn.edu (Postfix) with ESMTPS id C75FCB4D for <ipv6@ietf.org>; Sat, 15 Jul 2017 18:37:45 -0500 (CDT)
Received: by mail-it0-f71.google.com with SMTP id r4so142937055ith.7 for <ipv6@ietf.org>; Sat, 15 Jul 2017 16:37:45 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umn.edu; s=google; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=oUaNGTyQOTftccZS1W3IAdGue2pqMZShqaEvEqMG71k=; b=YcTSQEfCQEnWw6BQxIJEnz257jXylaQNC55nWyUSnPedf6Ap0AxnhwGRVMKdkC6xIN bt9RJXzb/705ZdCxpa4mwEIbKEhBQxulmCcLHWN1KAQi6Fu2DZT3H+yBQo65C5Uh0Gj6 jfvKvxKkiQVwvXUH9IeNBe7tTWGWDGMNxQhG0ED+9GBvo9JfgioJ4X4mREP4pge8k5dG ED5x8VHiOJ5g0asKxc2FIpKIM95MVmHtn9GUz0WX/dEEkcTrFy6rjx/6METfjJc8TwCR jHE0NRYqGCduAwIHNWMEhzSqUWU4BdHoqNIaLAs4eQXSnj7FehnfcT5LhCrEegWXWwvn ubYA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=oUaNGTyQOTftccZS1W3IAdGue2pqMZShqaEvEqMG71k=; b=diq1kz+ERRlN5XlMUbc+mynnC6ec04DRPcjZqDzuoxqzaEMeZqumw2TkVlNPTT0z/c VTdUxNv5p7/2KhfEpEi7j71rHgU1AvIJp+8uEWIhSdHoST002cgJ3VlIL5bgkzlgjUPR NY3NqlIz2FsQFe1yhOqbi5Wpjgn/Q1O7opXB+t30fruUl/IkOhE6YXF4dV5ySJgbtJG4 pSj+dPbPGDAPFFfFGKOqnbM+AivgzY35Toy2wRmEWfm+iRcuT4jeeGXQH0r3X4EVzoY9 L54jXk+XJUi3QMI7c6roZ2KsRzbnj8+qQNfknZKa/VrSAeWFOQie7nqCJNfXMAc/sV/r /WuQ==
X-Gm-Message-State: AIVw113aNZZhXmLZR+QTxxuPpfLwyo6mGwonlA6NYDCntiO6ChyiFh5n +g6dyM18kC+4oNcuX4R/Hnlkp5Wd/uGy8fUA3PpjE/XgdrTLpQMUeWT+9hvSbwKJDvQk0wrdq04 =
X-Received: by 10.36.22.17 with SMTP id a17mr583986ita.40.1500161864946; Sat, 15 Jul 2017 16:37:44 -0700 (PDT)
X-Received: by 10.36.22.17 with SMTP id a17mr583978ita.40.1500161864762; Sat, 15 Jul 2017 16:37:44 -0700 (PDT)
Received: from [10.174.89.216] (mobile-166-175-56-16.mycingular.net. [166.175.56.16]) by smtp.gmail.com with ESMTPSA id g26sm2496364ioj.62.2017.07.15.16.37.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 15 Jul 2017 16:37:43 -0700 (PDT)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (1.0)
Subject: Re: IPv6 Routing & ND vs. Addressing, (Was: Re: <draft-ietf-6man-rfc4291bis-09.txt>)
From: David Farmer <farmer@umn.edu>
X-Mailer: iPhone Mail (14F89)
In-Reply-To: <6a23ce43-89c3-0b37-a2da-70d40ba48b53@gmail.com>
Date: Sat, 15 Jul 2017 18:37:42 -0500
Cc: Nick Hilliard <nick@foobar.org>, Ole Troan <otroan@employees.org>, ipv6@ietf.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <AAA57E96-F827-4563-9950-285FBF1A603D@umn.edu>
References: <CAN-Dau2zgthR2w9e5ZVUdGc-vm+YvK2uTUJ8O=vrcv0jNc58RA@mail.gmail.com> <CAN-Dau1bxm5y0v_6kUBc_ym39bSSxepjdwrzcS7YHWD=CV9-bw@mail.gmail.com> <3b34d6e9718a45ae80877e36fb55f2b4@XCH15-06-11.nw.nos.boeing.com> <CAO42Z2x+282VK7nMFHjcCz9tBmJ_=d4OhkiRZFZDLcZhakGB1Q@mail.gmail.com> <30cb27b2-007a-2a39-803d-271297862cae@gmail.com> <40d757eb97564bc8bb0511063bd9d3f4@XCH15-06-11.nw.nos.boeing.com> <CAO42Z2x7ER2fUietjT3Ns-jpCqscCmVDVubiM0Dgw1_L0bkw=A@mail.gmail.com> <c7b140bf69104cd3877a7da03fbf17e7@XCH15-06-11.nw.nos.boeing.com> <32924d19-e5ce-7606-77f4-925b682065f5@gmail.com> <745583ab45bb407a9a210020a96773c5@XCH15-06-11.nw.nos.boeing.com> <m1dVbRc-0000GQC@stereo.hq.phicoh.net> <b6da9e67-1f4e-8900-5a3b-575d0c6fd2fd@gmail.com> <m1dWNIL-0000FpC@stereo.hq.phicoh.net> <3d2f1182-ec 19-959e-a63f-ad0d316bbacf@gmail.com> <BBC09C3B-BBA7-4B40-A44C-D6D7FB306314@employees.org> <596A8A5 2.9030108@foobar.org> <FCEE7BF1-A276-4243-B9CC-FE2BDE25183C@employees.org> <596A95B7.6000408@foobar.org> <6a23ce43-89c3-0b37-a2da-70d40ba48b53@gmail.com>
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/6KdJ2mjIOco-sP6zxvUk9SxwsXg>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 15 Jul 2017 23:37:49 -0000

> On Jul 15, 2017, at 17:41, Brian E Carpenter <brian.e.carpenter@gmail.com> wrote:
> 
>> On 16/07/2017 10:22, Nick Hilliard wrote:
>> Ole Troan wrote:
>>> This a protocol problem. DAD is built with the assumption that
>>> physical links are reliable. 20% packet loss for multicast is common
>>> on wifi...
>> 
>> most protocols will croak at 20% packet loss.  If wifi cannot support
>> multicast properly, then this is an 802.11 problem rather than a problem
>> with DAD or any of the many other bits of ipv6 that depend on moderately
>> reliable multicast.    
> 
> I'm curious. If DAD has that problem, why doesn't Neighbor Discovery
> have an equally bad problem?
> 
> BTW, Ole is correct. While testing the GRASP prototype at the last IETF,
> we discovered a high loss rate for LL multicast on the network.
> However, it wasn't primarily due to WiFi. It was due to intentional
> multicast throttling in the switches:
> https://mailarchive.ietf.org/arch/msg/anima/g4SUu-Bhkew-54hiJF1VPP8tfcQ

Wifi APs, especially enterprise grade Wifi APs, frequently do arp and ND proxy, and they convert the responses from the proxy to unicast at the 802.11 layer. Sometimes they even only do unicast at the 802.11 layer and replicate all multicast into 802.11 unicasts. Frequently this is more efficient than multicast because of the differences between the basic rate encoding used for multicast packets vs the usually much higher density encoding used for unicast packets.

That usually keeps things working well enough.

v2.23.0 | Report a Bug | By Email